Churning rhythm and seemingly minimalist, rigorously-controlled melodic patterns characterise three of Frederic Rzewski’s early works presented by the audacious and superbly accomplished Italian new-music ensemble Alter Ego.

Coming Together and Attica date from 1971-72, and were written in response to specific incidents in the wake of the 1971 prisoners’ revolt at New York’s Attica State Prison, an event that ended in violent, tragic consequences. Both works employ texts that are spoken with agonising deliberation, systematic repetition and long spaces between words. As a result, one senses, in Coming Together, the inner turmoil beneath the plain yet ambiguous language of a letter written by Sam Melville (one of the prisoners killed in the uprising), even through Frankie HI NRG’s heavily accented English pronounciation.

For Attica, Rzewski’s intense, raspy delivery of the line ‘Attica is in front of me’ effectively contrasts to the musicians’ suave, lyrical interplay, quite different from Group 180’s faster, harder-edged recording of the piece.

Rzewski’s 1969 Les Moutons de Panurge encompasses a steadily accelerating unison line whose sequence of notes gradually accumulates and diminishes. In this concert performance, an added live electronic component by Marco Passarani starts with scattered handclaps and gradually escalates into massed crowd noises that only the enthusiastic audience response can possibly top.

Main Drag finds Rzewski revisiting these compositional techniques as phrases from an eight- note scale deftly ricochet from one instrument to the next like restless pinballs. This is followed by Passarani’s driving, propulsive remix of the original by Robin Rimbaud, aka Scanner.

The disc also offers remixed interpretations of Attica and Les Moutons de Panurge. Both reveal how well Rzewski’s methodology lends itself to the sound world of contemporary dance and ambient music – Robin Rimbaud, for instance, compresses Main Drag’s single notes into murky chords that fly over a background of fleeting static. Giuseppe Ielasi gently crushes Attica’s lyrical lines into a canvas of B flat major jelly, with soft, insect-like blips dancing over it. Rzewski, of course, was doing similar stuff more than 30 years ago with Musica Elettronica Viva on far less sophisticated sound and recording equipment, but that’s another story.